Virtual image display apparatus

ABSTRACT

A virtual image display apparatus includes a case member that stores a image element and is provided with a first end connected to other members, an optical component holding member with which an optical component guiding image light from the image element is assembled and that is provided with a second end connected to the first end, three or more protruding portions that are provided at one of the first end and the second end, have protrusion shapes, and extend toward the other end, three or more grooves that are provided at the other end, have depression shapes corresponding to the three or more protruding portions, and extend, and adhesive portions that fix the three or more protruding portions to the three or more grooves in a state in which the case member is aligned with the optical component holding member.

This is a Continuation of U.S. application Ser. No. 15/428,598 filedFeb. 9, 2017, which claims the benefit of Japanese Application No.2016-143106 filed Jul. 21, 2016. The disclosures of the priorapplications are hereby incorporated by reference therein in theirentireties.

BACKGROUND 1. Technical Field

The present invention relates to a virtual image display apparatus whichpresents a video formed by a image element or the like, to an observer.

2. Related Art

As a virtual image display apparatus such as a head mounted display(hereinafter, referred to as an HMD in some cases) mounted on the headof an observer there is a display apparatus including a case memberstoring a image element and the like, and a lens barrel member storingan optical system which guides a video to the eyes of an observer. Inorder to assemble the lens barrel member, tabular members are providedwhich extend from upper and lower sides of the case member storing theimage element toward the lens barrel member, and the case member isfixed to the lens barrel member via a UV adhesive (ultraviolet curableresin) while the lens barrel member is vertically interposed between thetabular members (for example, refer to JP-A-2014-186201).

However, the above configuration for fixation using a pair of upper andlower tabular members may be strong against a vertical(upward-and-downward direction) external force but may be weak against ahorizontal (leftward-and-rightward direction) external force. Forexample, in a case where miniaturization of an apparatus furtherprogresses so that a gap with another member is reduced, and thusexternal forces are easily received from various directions, there isconcern that deviation may occur when a case member and a lens barrelmember are assembled with each other.

SUMMARY

An advantage of some aspects of the invention is to provide a virtualimage display apparatus which can achieve miniaturization thereof andhas a structure which is strong against an external force (externalpressure) applied to a joint portion.

A virtual image display apparatus according to an aspect of theinvention includes a case member that stores a image element and isprovided with a first end connected to other members; an opticalcomponent holding member with which an optical component guiding videolight from the image element is assembled and that is provided with asecond end connected to the first end; three or more protruding portionsthat are provided at one of the first end and the second end, haveprotrusion shapes, and extend toward the other end; three or moregrooves that are provided at the other end, have depression shapescorresponding to the three or more protruding portions, and extend; andadhesive portions that fix the three or more protruding portions to thethree or more grooves in a state in which the case member is alignedwith the optical component holding member, in which, among the three ormore protruding portions, at least one protruding portion is disposed onan opposite side to one or more other protruding portions with a displayregion of the image element interposed therebetween. Storing the imageelement indicates that the image element is held so as not to be moved,and includes, for example, a case where the image element is supportedor fixed in a state in which a part thereof is exposed.

In the virtual image display apparatus, in the case member and theoptical component holding member, one end is provided with three or moreprotruding portions, the other end is provided with three or moregrooves respectively corresponding to the three or more protrudingportions, and the protruding portions and the grooves are fixed to eachother at the adhesive portions. In this case, among the three or moreprotruding portions, at least one protruding portion is disposed on anopposite side to one or more other protruding portions with the displayregion of the image element interposed therebetween. In other words,since three or more fixation locations are provided, supporting andfixation locations can be increased and distributed, and thus it ispossible to form a structure which is strong against external force fromvarious directions such as a vertical direction or a horizontaldirection. The three or more protruding portions structurally extendfrom one end of the case member and the optical component holding membertoward the other end, and thus the apparatus can be miniaturized.

In a specific aspect of the invention, the three or more protrudingportions are disposed at positions corresponding to a peripheral sideforming an edge portion of the case member so as to be separated fromeach other. In this case, the three or more protruding portions areseparated from each other, and thus stable supporting and fixation canbe performed.

In another aspect of the invention, among the three or more protrudingportions, at least one protruding portion is disposed on an oppositeside to two or more other protruding portions with the display region ofthe image element interposed therebetween. In this case, for example,alignment can be reliably performed on other optical systems in which anemission direction of video light which is two-dimensionally emittedfrom the image element is taken into consideration, and fixation afterthe alignment can also be reliably performed.

In still another aspect of the invention, among the three or moreprotruding portions, two or more protruding portions are disposed alongone side of the image element in a longitudinal direction of the displayregion of the image element. In this case, the case member and theoptical component holding member can be stably fixed to each otherwithout increasing a length in a longitudinal direction. The three ormore protruding portions can be stably fixed while disposing two or moreprotruding portions along one side of the image element and adjusting,for example, a direction of a light emission surface of the imageelement along an edge of a display region by using the three or moreprotruding portions.

In still another aspect of the invention, the three or more protrudingportions are formed of four protruding portions disposed to correspondto four corners of the case member. In this case, strong fixation can beperformed by the four protruding portions.

In still another aspect of the invention, the virtual image displayapparatus further includes a wiring member that is located near thefirst and second ends and is disposed on a lateral side on whichexternal force is applied to the adhesive portions from a directionwhich is perpendicular to a direction in which the first end and thesecond end are connected to each other. In this case, for example, it ispossible to miniaturize the apparatus by disposing the wiring membernear the first and second ends and also to maintain high assemblingaccuracy due to the protruding portions or the like.

In still another aspect of the invention, each of the three or moregrooves has wall surface portions formed of a plurality of surfaces. Inthis case, two-dimensional fixation can be performed by a plurality ofsurfaces of the wall surface portion, and thus it is possible to form astructure which is strong against external force (external pressure)from various directions corresponding to the respective surfaces.

In still another aspect of the invention, each of the three or moreprotruding portions has a prismatic shape, and, in each of the three ormore grooves, the wall surface portion is formed of a plurality ofsurfaces corresponding to a surface shape of a corresponding protrudingportion. In this case, the prismatic surface is locatedtwo-dimensionally close to the wall surface portion, and thus it ispossible to form a structure which is strong against external force(external pressure) applied to the two-dimensional location.

In still another aspect of the invention, the wall surface portion isformed of three or more surfaces which are respectively directed inthree directions which are orthogonal to each other. In this case, it ispossible to form a structure which is strong against external force(external pressure) from three directions.

In still another aspect of the invention, two of the three directionswhich are perpendicular to each other are directions which areorthogonal to an optical axis direction of the image element and theoptical component. In this case, it is possible to form a structurewhich is strong against external force (external pressure) fromdirections which are orthogonal to the optical axis direction.

In still another aspect of the invention, the three or more protrudingportions are disposed to be symmetric to each other with respect to theimage element. In this case, for example, in a case of a pair of leftand right configurations, the protruding portions for the right eye andthe left eye can be manufactured in the same shape.

In still another aspect of the invention, the adhesive portions areformed of an adhesive filling the respective grooves when the three ormore protruding portions are respectively fixed to the three or morecorresponding grooves. In this case, it is possible to form the adhesiveportions which are reliably connected through fixation using theadhesive.

In still another aspect of the invention, the adhesive portions areformed of an ultraviolet curable resin. In this case, reliable fixationcan be performed in a short period of time through irradiation withultraviolet light (ultraviolet rays).

Instill another aspect of the invention, the first end is provided withthe three or more protruding portions, and the case member includes alow reflection coating portion that is provided on at least a surfacedisposed on a light emission side in the vicinity of the image element,and a surface portion including the three or more protruding portions.In this case, the low reflection coating portion can prevent unexpectedreflection and scattering of light, and can form surface unevenness onthe protruding portions so as to enhance adhesiveness.

In still another aspect of the invention, the low reflection coatingportion is formed on a surface portion including inclined surface whichis inclined with respect to the image element. In this case,particularly, it is possible to prevent reflection and scattering at alocation where unexpected light is easily generated.

In still another aspect of the invention, each of the three or moreprotruding portions has an embossed structure. In this case, it ispossible to further increase an adhesive strength by providing theembossed structure.

In still another aspect of the invention, of the first end and thesecond end, an end provided with the three or more protruding portionsis provided with three or more support portions that are provided torespectively correspond to the three or more protruding portions,thicker than the three or more protruding portions, and respectivelysupport the three or more protruding portions. Here, the support portionbeing thicker than the protruding portion indicates that each supportportion has a larger width or thickness than that of each protrudingportion, or each support portion is larger than each protruding portionin a case where sizes of sectional shapes thereof are compared with eachother. In this case, it is possible to make a structure of a jointlocation between the first end and the second end stronger by using thethree or more support portions.

In still another aspect of the invention, each of the first end and thesecond end is provided with a void forming portion that is provided at anon-adhesive location and forms a void, and the virtual image displayapparatus further includes a sealing member that seals the void formedby the void forming portion. In this case, it is possible to prevententry of refuse or the like by the sealing member and also to furtherincrease the rigidity of a joint location.

In still another aspect of the invention, the image element includes anFPC portion, and the case member includes an FPC holding portion thatcovers and holds connection locations between the FPC portion of theimage element and other members. In this case, it is possible toreliably protect the FPC portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a perspective view for explaining an exemplary exterior of avirtual image display apparatus according to a first embodiment.

FIG. 2 is a diagram for conceptually explaining an optical path of videolight.

FIG. 3 is a diagram for explaining that an optical system is held by anoptical component holding member.

FIG. 4 is a perspective view illustrating a state in which a case memberand the optical component holding member are assembled with each other.

FIG. 5 is a perspective view illustrating an exterior in which a displaydevice unit is viewed from a certain angle.

FIG. 6 is perspective view illustrating an exterior in which a displaydevice unit is viewed from another angle.

FIG. 7 is a front view of the display device unit.

FIG. 8 is a side sectional view of the display device unit.

FIG. 9 is a side sectional view of the case member in the display deviceunit.

FIG. 10 is an enlarged perspective view of an adhesive location betweena first end portion of the case member and a second end portion of theoptical component holding member.

FIG. 11 is a diagram for conceptually explaining examples of proceduresof assembling the case member and the optical component holding member.

FIG. 12 is a diagram for explaining a relationship between a flatsurface portion and a protruding portion in a groove.

FIG. 13 a plan view for explaining external force applied to theprotruding portion.

FIG. 14 is a side view for explaining external force applied to theprotruding portion.

FIG. 15 is a plan view for explaining an example of a virtual imagedisplay apparatus according to a second embodiment.

FIG. 16 is a diagram for explaining a display device unit according to amodification example.

FIG. 17 is a diagram for explaining a display device unit according toanother modification example.

FIG. 18 is a diagram for explaining a display device unit according tostill another modification example.

FIG. 19 is a diagram for explaining a modification example of the firstend portion.

FIG. 20 is a diagram for explaining a modification example of theprotruding portion and the groove.

FIG. 21 is a diagram for explaining a modification example of thevirtual image display apparatus.

DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment

Hereinafter, a description will be made of a virtual image displayapparatus according to a first embodiment of the invention withreference to FIG. 1 and the like.

As illustrated in FIG. 1, a virtual image display apparatus 100 of thepresent embodiment is a head mounted display (HMD) having an exteriorlike spectacles, and an observer or a user wearing the virtual imagedisplay apparatus 100 can visually recognize image light (video light)based on a virtual image and can also visually recognize or observe anexternal image in a see-through manner. The virtual image displayapparatus 100 includes a first display device 100A, a second displaydevice 100B, and a frame 102.

The first display device 100A and the second display device 100B arerespectively elements forming a right eye virtual image and a left eyevirtual image, and respectively include first and second optical members101 a and 101 b which cover the eyes of the observer in a see-throughmanner, and first and second image forming main bodies 105 a and 105 b.As will be described later, each of the first and second image formingmain body 105 a and 105 b is formed of a display device (image element)or an optical system for forming an image, such as a projection lens, amember storing the optical system, and the like. The display device(image element) or the projection lens is covered with a cover-likeouter member 105 d so as to be supported and stored. The first andsecond optical members 101 a and 101 b are light guide portions whichguide video light formed by the first and second image forming mainbodies 105 a and 105 b and allow external light and the video light tobe visually recognized in an overlapping manner, and a light guidedevice is formed of the first and second optical members 101 a and 101b. Hereinafter, the first optical member 101 a or second optical member101 b will also be referred to as a light guide device 20. Each of thefirst display device 100A and the second display device 100B alsofunctions as a virtual image display apparatus alone.

The frame 102 is an elongated member which is bent in a U shape in aplan view, and is a metallic integrated component. Here, as an example,the frame 102 is formed of a main body portion 102 p including amagnesium frame (magnesium alloy) which is a metallic integratedcomponent. As illustrated, the frame 102 includes a central portion 102a having a thick structure which is provided to be connected to both ofthe first optical member 101 a and the second optical member 101 b (thelight guide devices 20 as a pair of light guide portions), and a supportbody 102 b which extends along the first and second optical members 101a and 101 b from the central portion 102 a and forms a location bent ina U shape.

The central portion 102 a is interposed between front end sides of thefirst and second optical members 101 a and 101 b so as to fix relativepositions thereof. The support body 102 b forms first and secondperipheral portions 102 c and 102 d which are portions bent in a Ushape, and is connected to the first and second optical members 101 aand 101 b at the first and second peripheral portions 102 c and 102 d.

Temples 104 which are string portions extending backward from both ofleft and right ends of the frame 102 are provided, and may be used tosupport the virtual image display apparatus 100 by being brought intocontact with the ears or the temples of the observer.

Hereinafter, with reference to FIGS. 2 and 3, a description will be madeof conceptual examples of a structure and the like for guiding videolight in the virtual image display apparatus 100. Devices guiding videolight are the first display device 100A and the second display device100B (refer to FIG. 1 or the like) as described above, but the firstdisplay device 100A and the second display device 100B have horizontallysymmetrical and the same structure, and thus the only first displaydevice 100A will be described, and a description of the second displaydevice 100B will be omitted. As illustrated in FIG. 2, the first displaydevice 100A includes an image display device 80 which forms video light,an image forming projection lens 30 which is stored in a lens barrelportion, and the light guide device 20 (first optical member 101 a)which guides the video light which has passed through the image displaydevice 80 and the projection lens 30. The light guide device 20 isformed of a light guiding and see-through light guide member 10 and asee-through light transmissive member 50.

The image display device 80 may be a image element (video displayelement) formed of, for example, a self-emitting element such as anorganic EL element. The image display device 80 may be configured toinclude, for example, not only a video display element (image element)which is a transmissive spatial light modulation device, but also adriving controller (not illustrated) which controls an operation of anillumination device (not illustrated) which is a backlight emittingillumination light to the video display element. As will be describedlater in detail with reference to FIG. 4 and the like, in the presentembodiment, the image display device 80 which is a image element isaligned with an optical system such as the projection lens 30incorporated into a holding member which will be described later in astate of being stored in a case-like member and being thus configured asa unit (module). A unit (module) in which the image display device(image element) 80 is stored in a case is referred to as a displaydevice unit (or a image element unit).

The projection lens 30 is a projection optical system including, forexample, a plurality of (for example, three) optical elements (lenses)arranged in the direction of the incidence side optical axis AX (opticalaxis direction; a z direction) extending as constituent elements, andthe optical components (optical elements or lenses) are stored andsupported in an optical component holding member 39 (refer to FIG. 3 orthe like) which is a lens barrel portion. Each of the optical elementsis formed of, for example, an aspherical lens including an axisymmetricaspherical surface and a non-axisymmetric aspherical surface, and canthus form an intermediate image corresponding to a display image in theinside of the light guide member 10 in cooperation with a part of thelight guide member 10 forming the guide device 20. The projection lens30 projects video light formed by the image display device 80 toward thelight guide device 20 so as to cause the video light to be incidentthereto.

As described above, the light guide device 20 is formed of the lightguiding and see-through light guide member 10 and the see-through lighttransmissive member 50. The light guide member 10 is a part of the prismtype light guide device 20 and is integrally formed therewith, but maybe recognized to be divided into a first light guide portion 11 on thelight emission side and a second light guide portion 12 on the lightincidence side. The light transmissive member 50 is a member (assistingoptical block) which assists the light guide member 10 in a see-throughfunction, and is integrally fixed to the light guide member 10 so as toform a single light guide device 20. The light guide device 20 isscrewed to, for example, the optical component holding member 39 (referto FIG. 3 or the like) so as to be positioned and fixed to theprojection lens 30 with high accuracy. Here, a component as an integralunit in which the projection lens 30 and the light guide device 20 areattached to the optical component holding member 39 will be referred toas an optical system unit LU.

The light guide member 10 has a first face S11 to a fifth face S15 asside faces having optical functions. Among them, the first face S11 andthe fourth face S14 are continuously adjacent to each other, and thethird face S13 and the fifth face S15 are continuously adjacent to eachother. The second face S12 is disposed between the first face S11 andthe third face S13. A half mirror layer is provided associated with asurface of the second face S12. The half mirror layer is a reflectivefilm (that is, a transflective film) having light transmissive property,and is formed by forming a metal reflective film or a dielectricmulti-film, and has an appropriate reflectance for video light.

The light transmissive member 50 is integrally fixed to the light guidemember 10 so as to form a single light guide device 20 as describedabove, and is a member (assisting optical block) assisting the lightguide member 10 in a see-through function. The light transmissive member50 has a first transmissive face S51, a second transmissive face S52,and a third transmissive face S53 as side faces having opticalfunctions. The second transmissive face S52 is disposed between thefirst transmissive face S51 and the third transmissive face S53. Thefirst transmissive face S51 is located on a face extending from thefirst face S11 of the light guide member 10. The second transmissiveface S52 is a curved face joined to and integrated with the second faceS12, and the third transmissive face S53 is located on a face extendingfrom the third face S13 of the light guide member 10.

Hereinafter, with reference to FIG. 2, a brief description be made of anoptical path of video light (here, video light GL). First, the videolight GL formed by the image display device 80 is projected toward thelight guide device 20 by the projection lens 30. In the light guidedevice 20, the light guide member 10 to which the video light GL fromthe projection lens 30 is incident guides the video light GL toward theeyes of the observer through reflection at the first face S11 to thefifth face S15. Specifically, first, the video light GL from theprojection lens is incident to the fourth face S14 so as to be reflectedat the fifth face S15, then incident to the fourth face S14 again fromthe inside so as to be totally reflected, then incident to the thirdface S13 so as to be totally reflected, and then incident to the firstface S11 so as to be totally reflected. The video light GL which istotally reflected at the first face S11 is incident to the second faceS12, so as to be partially transmitted through the half mirror layerprovided on the second face S12 and be also partially reflected thereat,and is then incident to the first face S11 again so as to passtherethrough. The video light GL having passed through the first faceS11 is incident to the eyes of the observer or positions equivalentthereto as substantially parallel light beams. In other words, theobserver observes an image on the basis of the video light as a virtualimage.

In the light guide member 10 of the light guide device 20, the thirdface S13 and the first face S11 are flat faces (diopter of about 0)which are substantially parallel to each other, the third transmissiveface S53 and the first transmissive face S51 are flat faces which aresubstantially parallel to each other, and thus aberration or the likedoes not occur with respect to external light. The third transmissiveface S53 and the first face S11 are flat faces which are substantiallyparallel to each other, and thus aberration or the like scarcely occurswith respect to external light. As mentioned above, the observer canobserve an external image without distortion, that is, can visuallyrecognize or observe the external image in a see-through manner.

The above-described configuration is also the same for the seconddisplay device 100B (refer to FIG. 1 and the like). Consequently, imagesrespectively corresponding to the left and right eyes can be formed.

Here, a description will be made of assembling of the optical systemhaving the above-described configuration. As illustrated in FIG. 3, thelight guide device 20 which is an optical component forming a lightguide optical system and the projection lens 30 which is an opticalcomponent forming a projection optical system are positioned and fixedvia the optical component holding member 39 with high accuracy. In theabove-described configuration, in order for the observer to visuallyrecognize an image at an intended position, the accuracy of alignment ofthe image display device 80 with respect to the optical system (that is,the optical system unit LU) fixed via the optical component holdingmember 39 is considerably important. Deviation during assembling ofrespective optical components or a certain extent of error in opticaldesign due to performance of each optical component inevitably occurs.Thus, in the present embodiment, assembling is performed to have anadjustment margin based on a certain extent of allowance and to takebalance between the right and the left in alignment of the image displaydevice 80 with respect to the optical component holding member 39(optical system unit LU), and thus final images are aligned.Particularly, in a case of the configuration of a pair of the right andthe left as in the present embodiment, is essential to perform highlyaccurate adjustment in the unit of a pixel so that an image for theright eye side and an image for the left eye side are visuallyrecognized in a state of exactly overlapping each other, and it isconsiderably important to perform highly accurate alignment between theimage display device 80 and the optical system such as the projectionlens 30. Specifically, it is necessary to fix a pair of the right andleft optical units LU (optical component holding member 39) sides sothat images are visually recognized at intended positions in order notto cause horizontal deviation when images based on binocular view arevisually recognized, and to maintain the accuracy of alignment of theimage display device 80 for each eye. If miniaturization of theapparatus further progresses under such a situation, gaps with othermembers are reduced, and thus external force (external pressure) iseasily received from various directions. Particularly, when the imagedisplay device 80 is assembled with the optical component holding member39, applied external force (external pressure) is easily received, andthere is higher concern that deviation may occur. In the virtual imagedisplay apparatus 100 according to the present embodiment, a connectionstructure which is strong against external force can be provided betweena display device unit DU configured by storing the image display device80 in a case member 88 (refer to FIG. 4 and the like) and the opticalcomponent holding member 39, that is, the optical system unit LU inwhich an optical component such as the projection lens 30 is assembled,and miniaturization of the apparatus can be achieved.

Hereinafter, with reference to FIG. 4 and the like, a description willbe made of a structure of the display device unit DU which is a imageelement unit including the image display device (image element) 80 and astructure of the optical component holding member 39 (optical systemunit LU). FIG. 4 is a perspective view illustrating a state in which thedisplay device unit DU is assembled with the optical component holdingmember 39 (optical system unit LU) storing the projection lens 30. Inthe first display device 100A and the second display device 100B, thedisplay device units DU have horizontally symmetrical and the samestructure, and thus only the left side is illustrated in FIG. 4 and willbe described, and description and the like of the right side will beomitted.

As illustrated in FIGS. 4 to 8, the display device unit DU is a unit(module) configured by storing the image display device (image element)80 in the case member 88. In other words, the image display device 80 isstored in the case member 88 which is a case portion through fitting,and is held so as not to be moved. In other words, the case member 88can be said to be a holding portion (panel holding portion) which holdsthe image display device 80. Particularly, in the present embodiment,the case member 88 forming the display device unit DU has a frame bodystructure in which a penetration hole is provided in the central portionas illustrated. The case member 88 has four protruding portions 88 w, 88w, . . . which are attachment portions and fitting portions as front endportions at a first end TP1 which is an end on a side joined to theoptical component holding member 39 in order to support the frame bodystructure and to perform attachment alignment with the optical componentholding member 39 (refer to FIG. 4). The case member 88 also includes aheat dissipation structure portion 88 a forming an opening OP in which apart of the image display device 80 is open, a display devicepositioning portion (image element positioning portion) 88 b whichpositions and fixes the image display device 80, and a mask portion 88 m(refer to FIG. 8) which is provided on a light emission side of videolight which is an opposite side to the heat dissipation structureportion 88 a or the display device positioning portion 88 b and removesunnecessary light from component light emitted from the image displaydevice 80. The case member 88 is manufactured, for example, byinjection-molding a resin material. As long as desired shape andstructure can be manufactured, the case member 88 may employ, forexample, a metallic member with high thermal conductivity, such asaluminum or magnesium, and may thus be a structural body formed of asingle member.

Hereinafter, in the case member 88, particularly, a shape and astructure of the first end TP1 which is a portion joined to the opticalcomponent holding member 39 will be described. For example, asillustrated in FIG. 4 or 5, in the optical component holding member 39,the first end TP1 includes the four protruding portions 88 w, 88 w, 88 wand 88 w which are formed in a protruding shape toward the opticalcomponent holding member 39 and extend along the optical axis direction(z direction); and four support portions 87 w, 87 w, 87 w and 87 wrespectively supporting the protruding portions; and first void formingportions 86 w, 86 w, 86 w and 86 w which are provided at non-adhesivelocations which are not adhered to the optical component holding member39, and form four voids VO, VO, VO and VO along with the opticalcomponent holding member 39 between the optical component holding member39 and the first void forming portions.

The four protruding portions 88 w, 88 w, . . . are disposed to beseparated from each other on peripheral sides of edge portions formingends on the optical component holding member 39 side in the case member88 having a rectangular frame body structure. More specifically, asillustrated, the four protruding portions 88 w, 88 w, . . . arerespectively disposed at four corners of the case member 88corresponding to four corners of the image display device 80 and atpositions of front end sides on the optical component holding member 39side, and each protruding portion 88 w is a prismatic (square columnar)portion which extends along the optical axis direction (z direction) andforms a front end portion of the first end TP1. Here, the fourprotruding portions 88 w, 88 w, . . . are disposed to be symmetricalwith respect to the image display device 80 which is a rectangular imageelement. In this case, for example, as illustrated in FIG. 7, among thefour protruding portions 88 w, 88 w, . . . , a set of protrudingportions PPa and PPb are disposed along one side of the image displaydevice 80 in a longitudinal direction (x direction) with respect to arectangular display region EA (that is, a region from which video lightis emitted) of the image display device 80, and another set ofprotruding portions PPc and PPd are disposed along another side of theimage display device 80 in the longitudinal direction (x direction) withrespect to the display region EA (that is, a region from which videolight is emitted) of the image display device 80. Consequently, the casemember 88 and the optical component holding member 39 can be stably andtightly fixed to each other without increasing a length in thelongitudinal direction. At least one protruding portion 88 w is disposedon an opposite side to two other protruding portions 88 w and 88 w withthe display region EA interposed therebetween. For example, a singleprotruding portion PPa can be said to be disposed on an opposite side totwo other protruding portions PPc and PPd with the display region EAinterposed therebetween. Since the four protruding portions 88 w, 88 w,. . . are disposed in the above-described way, the four protrudingportions 88 w, 88 w, . . . are tightly fixed, and thus a direction ofthe rectangular display region EA which is a two-dimensional region ofthe image display device 80 can be fixed in a desired state with respectto the optical axis direction of the projection lens 30 or the like,that is, the incidence side optical axis AX (refer to FIG. 2 or thelike).

The four support portions 87 w, 87 w, . . . are provided further towardthe root sides than the four protruding portions 88 w, 88 w, . . . , andare portions which have larger widths or thicknesses (in other words,thicker than the four protruding portions 88 w, 88 w, . . . ) in the xdirection or the y direction than those of the four protruding portions88 w, 88 w, . . . , and thus support the four protruding portions 88 w,88 w, . . . . In other words, the first end TP1 has a shape which isthinned stepwise toward the front end side from the root side close tothe image display device 80.

The four first void forming portions 86 w, 86 w, 86 w and 86 w areprovided at portions between the respective protruding portions 88 wwhich are disposed to be separated from each other in the first end TP1and at non-adhesive locations which are not adhered to the opticalcomponent holding member 39, unlike the protruding portions 88 w, 88 w,. . . . More specifically, the first void forming portion 86 w isprovided in a U shape by an edge portion from a bridge-like portionbetween the adjacent support portions 87 w and 87 w to each of thesupport portions 87 w and 87 w. The four first void forming portions 86w, 86 w, 86 w and 86 w respectively form the four voids VO, VO, VO andVO between the first end TP1 and a second end TP2 along with four secondvoid forming portions 36 w, 36 w, 36 w and 36 w (refer to FIG. 4 or thelike) provided at the second end TP2 of the optical component holdingmember 39 which will be described later.

In the present embodiment, as illustrated, the case member 88 isprovided with the heat dissipation structure portion 88 a, and supportsand fixes (stores) the image display device 80 in a state in which theopposite side to the location from which video light is emitted is openand exposed in the image display device 80. Consequently, a heatdissipation effect is increased. Although not illustrated, for example,a heat conductive tape may be directly bonded to a portion exposed fromthe case member 88 in a rear portion of the image display device 80 soas to provide a heat dissipation portion, and thus heat dissipation inthe image display device 80 may be prompted. In a case where theabove-described so-called self-emitting image display device (imageelement) 80 is applied to an HMD, and thus a high luminance image is tobe formed, the image display device 80 has a structure in which a lightemitting source is provided in a panel board, and a driving driver IC, apower supply element, and the like are built thereinto. Thus, anincrease in an internal temperature tends to be problematic.Particularly, in a case where an organic EL (OLED) panel is applied to apanel of the image display device (image element) 80 as in the presentembodiment, there is concern that performance deterioration or areduction in the service life may notably occur due to the increase inan internal temperature, with regard to characteristics thereof. Inorder to handle this problem, efficient heat dissipation can beperformed by exposing a part of a silicon (Si) substrate SS forming theimage display device 80 in the heat dissipation structure portion 88 aof the case member 88, and further providing a heat dissipation portionformed of a heat conductive tape as necessary. In the above-describedconfiguration, it is possible to improve assembling position accuracy ofthe case member 88 and the image display device 80 by using an endsurface of the silicon substrate SS of the image display device 80.

Hereinafter, a description will be made of details of a structure of theimage display device 80 in the display device unit DU. As illustrated,the image display device 80 includes a rectangular tabular main bodyportion 80 a stored in the case member 88, and a flexible printedcircuit (FPC) portion 80 f which is connected to and extends from themain body portion 80 a. Above all, the main body portion 80 a, includes,as illustrated in FIGS. 5 to 7, the silicon substrate SS on whichvarious circuits are disposed and which forms an appearance of the mainbody portion 80 a; a light emitting portion 80 k which is an organic ELelement configured to include an organic EL material and generates colorlight which will become video light; and a protection glass GG forsealing which seals the light emitting portion 80 k along with thesilicon substrate SS. The image display device 80 performs a lightemission operation in response to a drive signal received from the FTCportion 80 f, and thus emits video light toward the protection glass GGside, that is, the +z side. As illustrated, the image display device 80is stored in the case member 88 in a state of a part of the main bodyportion 80 a being exposed. More specifically, the image display device80 is supported and fixed in a state of the entire rear surface SSr ofthe silicon substrate SS disposed on the opposite side to the locationfrom which video light is emitted being exposed.

Here, as described above, in the present embodiment, regarding aconfiguration of the image display device 80, the silicon (Si) substrateis employed as a self-emitting type element substrate mounted with anorganic EL element (OLED). Consequently, first, high thermalconductivity can be provided in relation to the above-described heatdissipation, and thus highly efficient heat dissipation can beperformed. In creation of a circuit board for configuring a lightemitting element, a circuit having a fine configuration, that is, a moreminute structure (for example, in the unit of several microns) can beformed. Since the silicon substrate forms an appearance of the imagedisplay device 80, each end surface of the silicon substrate is cut withhigh accuracy by using an accurate height (for example, within severaltens of μ in terms of manufacturing error) in silicon dicing, so as tobe used for positioning when the image display device 80 is stored inthe case member 88, and thus position accuracy with respect to the casemember 88 can be heightened (for example, much higher than that of asurface of the protection glass GG). Since the case member 88 aligns thedisplay device unit DU having the image display device 80 builtthereinto with the optical component holding member 39 storing theprojection lens 30, the accurate height is maintained in the displaydevice unit, and, as a result, position accuracy of the image displaydevice 80 with respect to the projection lens 30 can be maintained in ahigh state.

For example, as illustrated in FIG. 8, in the image display device 80,the FPC portion 80 f is connected to an end of the main body portion 80a which is a display element, and the connection location is coveredwith an FPC holding portion 88 p which is a part of the case member 88.In other words, the case member 88 includes the FPC holding portion 88 pprovided to cover the end of the FPC portion 80 f or the connectionlocation between the FPC portion 80 f and the main body portion 80 a atthe location where the FPC portion 80 f extends from the end of the mainbody portion 80 a. The image display device 80 includes a protrudingportion 80 x which extends to protrude toward the location where the FPCportion 80 f extends on the rear surface side of the FPC portion 80 f atthe end of the main body portion 80 a of the image display device 80,and the FPC portion 80 f is interposed between the protruding portion 80x and the FPC holding portion 88 p. Consequently, the connectionlocation between the FPC portion 80 f and the main body portion 80 a canbe protected, and unexpected disconnection is not made to occur in theFPC portion 80 f. The protruding portion 80 x may be formed of, forexample, an adhesive, and may be formed of the silicon substrate SS bylengthening a part of the silicon substrate SS. A fixation adhesive maybe applied around the FPC holding portion 88 p or the protruding portion80 x so that the respective portions including the main body portion 80a are fixed.

For example, as illustrated in FIG. 9, the heat dissipation structureportion 88 a of the case member 88 is formed as a groove portion havinga U shape which is open toward the +y side on the rear surface side (theopposite side to the location from which video light is emitted), thatis, the −z side in the figure, and is a portion into which the main bodyportion 80 a of the image display device 80 is inserted.

Hereinafter, referring to FIG. 4 again, a description will be made of astructure of the optical component holding member 39. Here, in theoptical component holding member 39, particularly, a shape and astructure of the second end TP2 which is an end on the side joined tothe case member 88 will be described. As illustrated, in the opticalcomponent holding member 39, the second end TP2 has four grooves 39 w,39 w, 39 w and 39 w formed in a depression shape so as to respectivelycorrespond to the four protruding portions 88 w, 88 w, 88 w and 88 w ofthe case member 88 and extend along the optical axis direction (zdirection); and the second void forming portions 36 w, 36 w, 36 w and 36w forming the four voids VO, VO, VO and VO along with the opticalcomponent holding member 39 between the case member 88 and the secondvoid forming portions. Each second void forming portion 36 w is providedat a portion between the respective grooves 39 w disposed to beseparated from each other in the second end TP2 and at a non-adhesivelocation which is not adhered to the case member 88. More specifically,the second void forming portion 36 w is provided in a linear shape byedges of the grooves 39 w and 39 w, and forms, for example, asemicircular void VO along with the corresponding first void formingportion 86 w.

The four grooves 39 w, 39 w, . . . are respectively provided atpositions corresponding to the four corners of the case member 88 in theoptical component holding member 39, so as to correspond to the fourprotruding portions 88 w, 88 w, . . . . Particularly, in an exampledescribed in the present embodiment, as an enlarged part (a set of thegroove and the protruding portion) is illustrated in FIG. 10, eachgroove 39 w has a wall surface portion FF formed of four flat surfacesFF1 to FF4 in accordance with the shape of each protruding portion 88 wwhich is a prismatic (square columnar) front end portion of the firstend TP1. More specifically, as illustrated, the four flat surfaces FF1to FF4 respectively face outer surfaces LS1 to LS4 of each squarecolumnar protruding portion 88 w. Among the flat surfaces FF1 to FF4,the first flat surface FF1 is directed in the horizontal direction (+xdirection), that is, a flat surface having the horizontal direction (xdirection) as a normal direction. The second flat surface FF2 isdirected in the upper direction (+y direction), that is, a flat surfacehaving the upper direction (y direction) as a normal direction. Thethird flat surface FF3 is directed in the optical axis direction (−zdirection), that is, a flat surface having the optical axis direction (zdirection) as a normal direction. The fourth flat surface FF4 is a flatsurface facing the first flat surface FF1 and is directed in thehorizontal direction (−x direction), that is, a flat surface having thehorizontal direction (x direction) as a normal direction. The flatsurfaces FF1 to FF4 are tightly fixed in a state of being close to theouter surfaces LS1 to LS4 of each square columnar protruding portion 88w. Therefore, a joint state between the case member 88 and the opticalcomponent holding member 39 can be made strong to the extent ofresisting against external force applied from various directions. Inother words, in the case of the above-described configuration, the firstflat surface FF1 to the third flat surface FF3 are respectively directedin three directions x direction, the y direction, and the z direction)which are orthogonal to each other, and thus a structure which is strongagainst external force applied from the three directions can beprovided. Among them, for example, the first flat surface FF1 and thesecond flat surface FF2 face directions (the x direction and the ydirection) which are perpendicular to the optical axis direction (zdirection), that is, directions directed toward the central side withrespect to a light emission direction of the panel surface which is avideo light emission surface. Since the intensity can be increased insuch directions, there can be provided a structure of stronglypreventing positional deviation against external force not only in thevertical direction (y direction) but also in the horizontal direction (xdirection), that is, the leftward-and-rightward direction.

As described above, a fixation location between the first end TP1 andthe second end TP2 is formed of the columnar protruding portions 88 w,88 w, . . . and the grooves 39 w, 39 w, . . . having the shapecorresponding thereto, and thus the fixation location can be formed in adot shape (or a linear shape). Particularly, in the above-describedconfiguration, at least one of the surface on the +y side or the surfaceon the −y side is exposed (in FIG. 10, the surface on the −y side isexposed as can be seen from corresponding FIG. 4). Therefore, in a casewhere fixation is performed by using, for example, an ultravioletcurable resin, an intervening adhesive in the x direction and the ydirection is exposed in the fixation location, and thus ultravioletlight can be thoroughly applied to the adhesive. An intervening adhesivein the y direction is shaded by the protruding portion 88 w duringirradiation, but, for example, a width of the protruding portion isabout 1 to 2 mm so as to be sufficiently small, and thus ultravioletlight can be thoroughly applied to the adhesive. As mentioned above, inthe present embodiment, the ultraviolet curable resin can be irradiatedwith ultraviolet light over the entire fixation location, and thusfixation can be reliably performed in a short period of time. Forexample, in a case where an adhesive is two-dimensionally applied to apair of tabular members and is cured, it cannot be said that ultravioletlight is sufficiently applied to a central side of a surface, and thusadhesion may be insufficiently performed, but, in a case of theconfiguration of the present embodiment, this situation can beprevented, and the adhesive can be reliably cured in a short period oftime. The protruding portion 88 w has the shape and the structure ofextending in the optical axis direction, and thus the apparatus can beminiaturized.

Hereinafter, with reference to FIG. 11, a description will be made ofassembling of the case member 88 and the optical component holdingmember 39 (assembling of the first end TP1 and the second end TP2).

First, as shown in step A, the case member 88 (that is, the displaydevice unit DU) and the optical component holding member 39 (that is,the optical system unit LU) are prepared (preparation step). Here, it isassumed that the optical component holding member 39 is fixed, and thecase member 88 and the optical component holding member 39 are attachedto jigs (not illustrated) so that a position of the case member 88 canbe adjusted in six-axis directions with respect to the optical componentholding member 39. Next, as shown in step B, in the optical componentholding member 39, an adhesive AH fills each groove 39 w of the secondend TP2. In other words, each groove 39 w is buried with the adhesive AH(adhesive filling step). Here, an ultraviolet curable resin is used asthe adhesive AH. Next, as shown in step C, the case member 88 is movedto the optical component holding member 39 side so that eachcorresponding protruding portion 88 w is inserted into each groove 39 wfilled with the adhesive AH, and alignment (six-axis alignment)regarding rotation axes in three directions is performed in addition tothe three directions including an upward-and-downward direction, aleftward-and-rightward direction, and a front-and-rear direction(alignment step). Next, as shown in step D, the adhesive AH isirradiated with ultraviolet light UV, and thus the adhesive AH is curedso as to form an adhesive portion AP. Therefore, the case member 88 isfixed to the optical component holding member 39, that is, theprotruding portion 88 w of the first end TP1 is fixed to the groove 39 wof the second end TP2 (fixation step). At this time, the void VO isformed by the void forming portions 86 w and 36 w. Finally, assemblingof other components or removal of refuse of the joint location or aperiphery thereof using the void VO is performed as necessary, and,then, as shown in step E, a tape-shaped sealing member SL seals the voidVO (sealing step).

Hereinafter, with reference to FIGS. 12 to 14, a detailed descriptionwill be made of characteristics of a joint state in a joint portion IFbetween the case member 88 and the optical component holding member 39(between the first end TP1 and the second end TP2), action applied tothe joint portion IF, and the like. For example, as illustrated in FIGS.12 and 13, if external pressure (external force) Fx is applied to thedisplay device unit DU in the horizontal direction (x direction),moments Mfx1 and Mfx2 may be generated in the protruding portions PPaand PPb among the protruding portions 88 w. In this case, the sameaction also occurs in the remaining protruding portions PPc and PPd.This may occur, for example, as illustrated, in a case where a harnessmember HP is disposed to pass near a horizontal side of the case member88 during assembling. In other words, if the harness member HP isdisposed to be biased toward the lateral side near the first end TP1 andthe second end TP2 (in the cases of FIGS. 12 and 13, the harness memberHP can be said to be biased to the left (−X side)), for example, duringassembling, the external force Fx may be applied from a direction (xdirection) which is perpendicular to the connection direction (zdirection) of the first end TP1 and the second end TP2. Even in thiscase, as described above, since the four protruding portions 88 w, 88 w,. . . are attached and fixed in a state in which the surface portions FFof the grooves 39 w are filled with the adhesive AH, the first flatsurface FF1 and the outer surface LS1 (and the fourth flat surface FF4and the outer surface LS4) are two-dimensionally fixed to each other inthe horizontal direction (x direction), and thus a configuration whichis sufficient to maintain the joint state with respect to the momentsMfx1 and Mfx2 is formed. For example, as illustrated in FIGS. 12 and 14,if external pressure (external force) Fy1 or external pressure (externalforce) Fy2 is applied to the display device unit DU from the upwarddirection or the downward direction (y direction), moments Mfy1 and Mfy2may be generated in the protruding portions 88 w. This may occur, forexample, as illustrated, in a case where tensile force works on the FPCportion 80 f disposed near the lower side of the case member 88 duringassembling, and thus the external pressure (external force) Fy1 isapplied. It can also be said that the FPC portion 80 f is disposed to bebiased to the lateral side near the first end TP1 and the second endTP2, and thus the external force Fy1 may be applied due to thisarrangement. Even in this case, in the same manner as described above,the second flat surface FF2 and the outer surface LS2 aretwo-dimensionally fixed to each other in the vertical direction (ydirection), and thus a configuration which is sufficient to maintain thejoint state with respect to the moments Mfy1 and Mfy2 is formed. Forexample, as illustrated in FIG. 13, if external pressure (externalforce) Fz is applied to the display device unit DU from the optical axisdirection (z direction), external forces Fz1 and Fz2 may be generated inthe protruding portions 88 w. Even this case, in the same manner asdescribed above, the third flat surface FF3 and the outer surface LS3are two-dimensionally fixed to each other in the optical axis direction(z direction), and thus a configuration which is sufficient to maintainthe joint state with respect to the external forces Fz1 and Fz2 isformed. In the above-described case, the four protruding portions 88 w,88 w, . . . are provided at four corners of the case member 88, and,thus, for example, two protruding portions 88 w and 88 w are linearlyarranged and separated from each other in the horizontal direction (xdirection). Consequently, for example, the influence of the externalpressure (external force) Fx illustrated in FIG. 13 is distributed, and,especially, the moment Mfx1 working at a position relatively close to alocation on which the external pressure (external force) Fx works isrelatively reduced. Therefore, it can be said that the rigidity isfurther increased. This is also the same for the vertical direction (ydirection).

In the above-described case, the four protruding portions 88 w, 88 w, .. . are disposed symmetrically with respect to the image display device80. In this case, image display devices for the right eye and the lefteye can be manufactured in the same shape.

In the above-described configuration, the fourth flat surface FF4 isprovided on the outside of the groove 39 w, and thus there is astructure in which the applied adhesive AH hardly overflows outward.However, in a case where there is no concern that the adhesive overflowsor there is no problem in the rigidity, the fourth flat surface FF4 maynot be provided.

As described above, in the virtual image display apparatus 100 accordingto the present embodiment, of the case member 88 and the opticalcomponent holding member 39, the four protruding portions 88 w, 88 w, .. . are provided at the first end TP1 of the case member 88, and thefour grooves 39 w, 39 w, . . . are provided at the second end TP2 of theoptical component holding member 39, and these are fixed to each otherat the adhesive portions AP. In other words, three or more fixationlocations are provided, and thus it is possible to form a structurewhich is strong against external force from various directions such as avertical direction or a horizontal direction. The protruding portion 88w structurally extends along the optical axis direction, and thus theapparatus can be miniaturized.

Second Embodiment

Hereinafter, with reference to FIG. 15, a virtual image displayapparatus according to a second embodiment will be described. Thevirtual image display apparatus according to the second embodiment isobtained by partially changing the virtual image display apparatus ofthe first embodiment, and FIG. 15 corresponds to FIG. 13. Portions whichare not particularly mentioned are the same as those in the firstembodiment.

As illustrated in FIG. 15, a virtual image display apparatus 200 isdifferent from the virtual image display apparatus 100 exemplified inthe first embodiment in that a front end portion of the first end TP1 ofa case member 288 is formed of three protruding portions 288W, 288W and288W, and a front end portion of the second end TP2 of the opticalcomponent holding member 239 is formed of three grooves 239W, 239W and239W so as to correspond thereto. Specifically, the first end TP1 of thecase member 288 has a set of (two) protruding portions PPa and PPbdisposed along one side of the image display device 80 in a longitudinaldirection (x direction) of the image display device 80, and a singleprotruding portion PPc disposed on an opposite side to the twoprotruding portions PPa and PPb with a display region of the imagedisplay device 80 interposed therebetween. As illustrated, theprotruding portion PPc is disposed at a position at an equal distance ora substantially equal distance from the protruding portions PPa and PPbon another side of the image display device 80. In other words,respective points corresponding to the three disposed protrudingportions PPa, PPb and PPc are symmetric while forming vertices anisosceles triangle. As illustrated, moments at the protruding portionsPPa and PPb generated in a case where the external pressure (externalforce) Fx is applied from the horizontal direction (x direction) aremoments Mfx1 and Mfx2 in the same manner as in the first embodiment, anda moment at the protruding portion PPc is a moment Mfx3.

Generally, when compared between a case where a single protrudingportion (protruding portion PPc) is provided at the center in thehorizontal direction (x direction) as in the present embodiment and acase where two protruding portions are provided as in the firstembodiment, a moment tends to further increase in the case where thesingle protruding portion is provided at the center. In other words, ina case of FIG. 15, there is a probability that the moment Mfx3 may belarger than the moments Mfx1 and Mfx2.

However, as described above, if fixation force at each protrudingportion is sufficiently great, and thus an adhesive strength sufficientto resist against the expected moment Mfx3 is ensured, joining can beperformed by using the three protruding portions as in the presentembodiment.

Also in the virtual image display apparatus 200 according to the presentembodiment, the first end TP1 is provided with three protrudingportions, the second end TP2 is also provided with three grooves, andthe protruding portions and the grooves are fixed to each other.Therefore, it is possible to form a structure which is strong againstexternal force from various directions such as a vertical direction or ahorizontal direction. The protruding portion structurally extends alongthe optical axis direction, and thus the apparatus can be miniaturized.

Others

The invention has been described on the basis of the embodiments, butthe invention is not limited to the embodiments, and may be implementedin various aspects within the scope without departing from the spiritthereof.

For example, as in a display device unit 380 illustrated as amodification example in FIG. 16, a low reflection coating portion ARwhich is formed by performing low reflection coating for preventingreflection and scattering of light may be provided on a surface (ahatched location in the figure) on the light emission side. In thiscase, if the low reflection coating portion AR is also formed on therespective protruding portions 88 w, 88 w, . . . in addition to alocation which is necessary to prevent unexpected reflection andscattering of light, surface unevenness is formed by the low reflectioncoating portion AR, and thus an adhesive strength at each protrudingportion 88 w can be increased. In the illustrated example, the lowreflection coating portion AR is formed on the surface on the lightemission side or the entire surface reaching the periphery thereof, butthe low reflection coating portion AR is provided on at least a surfaceportion forming a surface disposed on the video light emission side inthe vicinity of the image display device 80, particularly, a surfaceportion including an inclined surface SP which is inclined with respectto the image display device 80, and a surface including the protrudingportions 88 w, 88 w, . . . , and thus an expected purpose can beachieved.

As illustrated in FIG. 17 as another modification example, an embossedstructure GS may be provided on a surface (a hatched location in thefigure) of the protruding portion 88 w of the display device unit. Theembossed structure GS is provided on the protruding portion 88 w, andthus an adhesive strength can be further increased. As illustrated inFIG. 18 as still another modification example, a groove structureportion DT may be provided on a surface of the protruding portion 88 wof the display device unit so that an adhesive strength can beincreased. As illustrated, the groove structure portion DT may have acutout shape along a direction in which the protruding portion 88 wextends, and thus release property during molding can be maintained. Forexample, a dimple shape may be formed on the surface of the protrudingportion 88 w. The embossed structure or the dimple shape may be formed,for example, by molding the protruding portion 88 w through injectionmolding and then processing the protruding portion.

Regarding the first end TP1 and the second end TP2, as long as the casemember 88 and the optical component holding member 39 can be connectedto each other, protruding portions may be expected to be provided atvarious positions on the end side of each member. For example, as in afirst end X1 shown as an example of the first end TP1 in FIG. 19, fourprotruding portions 88 w, 88 w, . . . may be formed at edges of fourcorners, but are not limited thereto, and, as in a first end X2 shown asanother example, protruding portions may be provided slightly inwardfrom the edges of the four corners.

In the above description, a shape of the protruding portion 88 w of thedisplay device unit is a square columnar shape, but may be polygonalshapes (for example, a triangular columnar shape or a pentagonalcolumnar shape). Specifically, for example, on the left part in FIG. 20,as in a protruding portion Y1 and a groove 21 shown as examples of theprotruding portion 88 w and the groove 39 w, the hexagonal columnarprotruding portion Y1 and the groove Z1 having a shape correspondingthereto may be formed. On the right part in FIG. 20, as in a protrudingportion Y1 and a groove Z2 shown as other examples of the protrudingportion 88 w and the groove 39 w, the protruding portion Y1 may have ahexagonal columnar shape, but the groove Z2 may have a shape (a squarecolumnar shape in the illustrated example) which is different therefrom.

In the above description, three or more (for example, four) protrudingportions 88 w, 88 w, . . . are provided at the first end TP1 of thefirst end TP1 and the second end TP2, and three or more (for example,four) grooves 39 w, 39 w, . . . are provided at the second end TP2, butthe protruding portions and the grooves may be provided reversely. Inother words, the second end TP2 may be provided with the protrudingportions 88 w, 88 w, . . . , and the first end TP1 may be provided withthe grooves 39 w, 39 w, . . . .

In the above description, the half mirror layer of the second face S12is, for example, a metal reflection film or a dielectric multi-layerfilm, but may be replaced with a planar or curved hologram element. Thefifth face S15 may be formed not only of a mirror reflection face butalso of a hologram element.

In the above description, the light guide member 10 or the like extendsin the direction in which the eyes are arranged, but the light guidemember 10 may be disposed to vertically extend. In this case, the lightguide members 10 have a structure of being disposed not in series but inparallel.

In the above description, a description has been made of an aspect inwhich image light overlaps external light, but the invention may beapplied to, for example, a virtual image display apparatus having anaspect in which only image light is observed without overlapping, or avirtual image display apparatus which switches between an aspect inwhich only image light is observed and an aspect in which only externallight is observed.

The technique of the invention may be applied to a so-called videosee-through product formed of a display and an imaging apparatus.

In the above description, the binocular-view virtual image displayapparatus including a pair of display devices has been described, butmay include a single display device. In other words, there may be aconfiguration in which an image display device or the like correspondingto only one of the right eye or the left eye is provided, and an imageis viewed with only the single eye.

In the above description, the case member has a frame body structure inwhich the penetration hole is provided at the center thereof, but is notlimited thereto. Case members having various shapes may be usedaccording to a necessary light emission amount, a situation of heatgeneration, a configuration of an image display device, or the like,and, for example, a case member may be used in which a penetration holeportion is formed in a mesh shape, or a case member which is formed in acasing state without a penetration hole may be used.

A unit in which the optical system unit LU and the display device unitDU are assembled with each other will be referred to as an opticaldisplay unit GU (for example, steps D and E in FIG. 11). In other words,the optical display unit GU indicates that the entire optical systemfrom a light source or a image element side to a light guide member sideis generated as a unit by using, for example, a lens barrel member(optical component holding member 39).

The configurations of the embodiments according to the invention may beapplied to an apparatus using a hologram element, such as a virtualimage display apparatus 300 exemplified in FIG. 21. Specifically, thevirtual image display apparatus 300 is formed of a display device unitDU in which a image element and the like are stored in a case member388, and a light guide device 320 configured to include hologramelements. The light guide device 320 is provided with a pair of hologramelements HE1 and HE2 on a light incidence side and a light emission sideof a light guide plate PL which is a tabular transparent member, and aprism-shaped projection member (projection prism) PR disposed on anoptical path front end side of the hologram element HE1 on the incidenceside. The light guide device 320 is assembled with an optical componentholding member 339 (for example, a metallic member). It is possible tomaintain miniaturization of the apparatus and to form a structure whichis strong against external force from various directions by using thefirst end TP1 provided in the display device unit DU and the second endTP2 provided in the optical component holding member 339.

In the above description, the case member has an integrated structure,but is not limited thereto, and, for example, the case member is formedto have a structure of two members (two components) to which a lightsource portion and a liquid crystal panel are respectively fixed. Thecase member may be formed of three or more members (three or morecomponents).

In a virtual image display apparatus having a pair of left and rightconfigurations, the harness member HP is disposed on the lateral side ofthe optical component holding member 39 or the like as described above,for example, at a location (for the left eye, for example) where a cablefrom a controller is connected as in the example illustrated in FIG. 1,but may be directly connected without passing the lateral side of theoptical component holding member 39 or the like at an opposite location(for the right eye). In other words, in this case, the harness member HPis configured to be provided on the lateral side of the opticalcomponent holding member 39 or the like on only one side of a pair ofleft and right configurations.

The entire disclosure of Japanese Patent Application No. 2016-143106,filed Jul. 21, 2016 is expressly incorporated by reference herein.

What is claimed:
 1. A virtual image display apparatus comprising: a casemember that stores an image element; and an optical component holdingmember which holds an optical component, wherein: the optical componentholding member has a first protruding portion, a second protrudingportion and a third protruding portion, the first protruding portion isattached to the case member with a first adhesive, the second protrudingportion is attached to the case member with a second adhesive, the thirdprotruding portion is attached to the case member with a third adhesive,the optical component holding member has a first groove in an area towhich the first adhesive contacts, the optical component holding memberhas a second groove in an area to which the second adhesive contacts,the first groove is arranged on one side where a display area of theimage element is located, and the second groove is arranged on ananother side which is an opposite side to the one side.
 2. The virtualimage display apparatus according to claim 1, wherein: the firstprotruding portion, the second protruding portion and the thirdprotruding portion protrude toward the case member.
 3. The virtual imagedisplay apparatus according to claim 2, wherein: the first protrudingportion has a first surface, which is a surface along a direction inwhich the first protruding portion extends, the second protrudingportion has a second surface, which is a surface along a direction inwhich the second protruding portion extends, a first groove of the casemember has a third surface which is a surface opposed to the firstsurface, a second groove of the case member has a fourth surface whichis a surface opposed to the second surface, the first surface is spacedapart from the third surface and the first adhesive is disposed in aportion where the first surface and the third surface are separated fromeach other, and the second surface is spaced apart from the fourthsurface and the second adhesive is disposed in a portion where thesecond surface and the fourth surface are separated from each other. 4.The virtual image display apparatus according to claim 3, wherein: thefirst protruding portion has a fifth surface, which is surface opposedto the first surface along a protruding direction of the firstprotruding portion, the second protruding portion has a sixth surface,which is surface opposed to the second surface along a protrudingdirection of the second protruding portion, the first groove of the casemember has a seventh surface, which is a surface opposed to the fifthsurface, the second groove of the case member has an eighth surface,which is a surface opposed to the sixth surface, the fifth surface isspaced apart from the seventh surface and the first adhesive is disposedin a portion where the fifth surface and the seventh surface areseparated, and the sixth surface is spaced apart from the eighth surfaceand the second adhesive is disposed in a portion where the sixth surfaceand the eighth surface are separated.
 5. The virtual image displayapparatus according to claim 2, wherein: a direction in which the secondprotruding portion extends is an optical axis direction, a direction inwhich the first protruding portion extends is the optical axisdirection.
 6. The virtual image display apparatus according to claim 2,wherein: each of the first adhesive and the second adhesive is anultraviolet curable resin.